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Sunday, January 7, 2018

As posted before, I have been playing with a new TEVO Little Monster 3D Printer, I have made a LOT of Noob mistakes that could have been avoided if I had only knew.

The following are notes to myself.

o. Do not turn off the power to the 3D Printer unless you are certain that the Hot-End has cooled down. if not, removing power to the 3D Printer will cause the filament to melt within the Cold-End and then a complicated repair method will be required to fix the problem.

o. Remember, 3D Printing is very SLOW, it is much slower than waiting for paint to dry.

o. Remember the hot-end is VERY HOT, I have several burns to remind me.

o. Learn how to set the Z zero Height to within a paper thickness of the print bed, or nothing will work correctly until you do, no mater how hard you try.

o. Buy several sets of Print Head replacement parts, for the; Cold-End, Thermal Break, and Hot-End.

o. Consider buying some Tetrahydrofuran (THF) , it is the only effective thing that will dissolve PLA (for Hot-End clean and repair), and it can be used to glue PLA parts together. Or at least that is what google suggests.

o. Note, MOST often Hot-End repair work will be done while it is HOT (about 210 C, or more), other wise PLA will be hard and not easily removed.

o. For my use, Blue Painter Tape works best for the Printer Bed, it has some texture that will show up on the printed part, but PLA stick very good to it. A roles of Blue Painters Tape (10 inches wide) are available on-line for about $50, and worth every penny, it makes bed prep very easy.

o. If the Hot-End is disassembled, for cleaning or repair, remember it has to be re-assembled and tightened while at intended operating temperature, for me that is about 215C. If not, it WILL leak.

Wednesday, September 20, 2017

Sorry, this is not an Amateur Radio post.
After many months of working with a 3D Printer, I have finally successfully created a working set of interlocking reduction gears, each section provides a 7:1 reduction. This device is about 2 inches in diameter, the total reduction is 14:1.

The original Ring Gear from Thingiverse was modified to create this multi-stage Reduction Gear. My contribution was to modify it as necessary and join two sets together.

Sketchup Model

The transfer plates (with the connecting pins) were assembled by adding the center HEX pin after printing. Each of the two Reduction Cluster were printer as an assembled single object on the printer. No cleanup or filing was necessary.

Silicon grease is used for lube.

I may increase the size (and with other modification) this could be used as a Light Weight Field Day Antenna Rotor.

Sunday, April 30, 2017

I purchased a 3D Printer, and just now learning how to use it, there is a lot to learn.

After many trials and failures, I have successfully printed the equivalent of "Hello World" for 3D Printers, which is the "3DBenchy". This online part was designed to be a torture test for a 3D Printer, with many under-cuts, over-hangs and fills, that are somewhat difficult. This part is about 2.5 inches long.

My Printed 3DBenchy Results

3DBenchy was actually about my 10th attempt at print anything, the first few parts went horribly wrong.

Here are a few of my initial prints of a part of my own design, obviously I did not know what I was doing.

Things got better with practice and understanding of the 3D Print process and control parameters.

The above is a replacement part for an Orbital Sander, this part is no longer available from the manufacture, it will eventually be printed with Black ABS Plastic, which is similar to the original. I designed this part with FreeCAD and used Slic3r for the G-Code output for the 3D Printer. For me, FreeCAD has a steep learning curve.

And, then . . .

On the next part, a Cable Chain of my own design, I must have lost the magic !!

But finally, things got better with practice.

Cable Chain Links

The First Two Links of a Cable Chain.

I am currently printing four Cable Links with newer/better design, I will report the results. For these link design, I have used Sketchup and Slic3r. For simple designs Sketchup is easy to use, as long as you only need "Union" style of object creation, that is, objects that touch are automatically joined together (union'd) when exported as an STL file. STL files are needed by Slic3r.

The main reason that it has be off-line, is lack of interest, and recently, I could only get the code to compile on the old Arduino IDE (Rev 1.6.x). The code is quite large and I took advantage of many "tabs" for code fragments, which are concatenated before presented to the compiler. The new Arduino IDE Revision (1.8.1) is much more strict regarding Header Files, code files, and program structure. There were just TOO MANY errors to correct to keep my interest in solving the problem.

Once started to solve the problems and not getting much accomplished, my Friend Jeff - Ko7m, suggest another IDE, he suggested "PlatformIO IDE".

With little work, I found and installed PlatformIO, but alas, I found similar problems and concerns with it. But little-by-little after much on-line reading, Jeff and I worked out the best file structures that worked with PlatformIO.

Saturday, January 14, 2017

Several years ago my trusty Weller Soldering Iron failed, knowing that most of my projects were going to use small SMD parts, I ordered a fancy replacement, a Hakko FX-888 Soldering Station (about $90.00) with several assorted tips, some really small tips for SMDs. The tracking information, revealed that it would be in my hands in about three weeks.

But, I needed a replacement Iron NOW, to finish a project. I went to Frys, and found a cheapy Iron that I thought I could use (about $29.00), it was a Hakko Presto 980-V12/P. It had only one smallish chisel tip, but I thought it could be used for some larger SMDs.

Well, now several years later, the expensive Hakko FX-888 with its small tips is VERY seldom used (maybe about 3%), while the cheap Hakko Presto 980-V12/P is used for most (if not all) of my projects, and I am still using the original TIP. If you have seen my projects (typically on a 0.5in x 0.7in PCB boards) you might think the FX-888 would be more appropriate, but I fould it is not.

The following are some of my projects where the Hakko Presto 980-V12/P was used:

Wednesday, December 7, 2016

I have finally found some time to "melt some solder" at my new location and new eShop bench. The bench is not finished yet, but I needed a Solder FIX.

This, like all of my project, is an attempt to make projects as small as my abilities allow.

New eShop Bench

The project that I am working on is some boards I just received back from OSH Park. The boards are a small and part of an experimental HF Receiver. The boards edge connectors are "Castellated" to allow them to be used within a larger PCB circuit, and with attached Headers, they can be used with/on a Solderless Proto Board.

The size of these boards are:
Left: 0.8x1.0 inch,
Right: 0.5x1.0 inch

This is my experimental design, it is a circuit that contain the: HF VFO Mixer, Band Pass Filter (BPF, 40MHz), and BFO Mixer.

The bigger boards on the left are similar to those on the right, except they also contains the Oscillators for both the VFO and the BFO, along with the voltage regulator for the oscillator chip.

The components on the lower half are installed
Ready for some testing
Unpopulated is the VFO/BFO and Voltage Regulator

LTSpice suggests this circuit will work, but assessing the actual performance is the real reason for building this experimental circuit.

Additional circuits will be needed, to make this a real receiver, like: Band Select Filters, Automatic Gain Control, Audio Circuit, a Microcontroller, and Display. Likewise, I will make each as small as I can.

Sunday, November 20, 2016

I have NOT posted anything for several (6) months, my life has been in somewhat of turmoil (maybe, I am getting too old for this), but now, maybe things are starting to get back to normal.

Regardless, I have been thinking of many HomeBrew projects that I want to build and blog. But first I have to set up my eShop in this new (and better) location.

This is the beginnings of my new eShop setup:

My new eShop Bench

I just finished building the wooden shelves. My previous eShop shelves were about the same but fixed, these shelves are movable, and therefore this setup should be more effective for varying sized electronic equipment.

Adjacent to that, is my current MS 10 WorkStation, Raspberry Pi, and Orange Pi set ups:

Computer Workstation

The three bottom screens are connected to the MS WorkStation, and the three uppers are for the PI's.

Note: and the refrigerator is only about 15 feet away, hihi.

Unfortunately, I have not started my Ham Station and Antenna System yet.

I have some small Ham Radio related PC boards out for manufacturing at OSH Park, if they works as expected, I may be blogging about those, soon.

UPDATE:
The day after installing my shelves and turning on the Oscope for the first time in a long while, the (calibration) trace is going bonkers, with a short bright spot at the beginning of the trace. Trace INTEN has little control. DANG, now something else to repair.
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Tuesday, May 3, 2016

For the last few weeks, my Son and I have been working on his F350 6.0L Diesel Engine, to replace; the Exhaust Gas Recirculation (EGR) Heat Exchanger, and the Oil Cooler. This work is a pain because most of the top of the engine, including the Turbo Charger has to be removed to get to the parts being replaced. There are several good Youtube video showing the details.

We ordered parts and gaskets bases on information available. This repair is somewhat of a difficult task due to engine compartment large size and the long reaches necessary to access everything. There is one very dirty mess when the Oil Cooler cover is removed, where about a quart of oil spills over the engine valley, but that cleanup marked the beginning of the actual part replacement and rebuild.

Most of the previously dis-assembled parts where replaced in the order they were removed without difficulty.

But Then

FORD FailedOil Drain Back and Oil Cooler Bypass Valve Assemble

On top of the Oil Cooler Cover there is a small assemble which is held in place with two screws within the Oil Filter Case (Can). This small assemble is about 3 inches wide.

This small assemble holds two valves; one to Drain Back oil from the Oil Filter Case (helpful during oil and filter changes), and the other is the Oil Cooler Bypass Value (OCBV) which opens in case the Oil Cooler get clogged up. These two valves are very simple; the first is held shut by gravity and can pressure; the other is a spring loaded Brass Plunger with a small flat plastic/rubber (of some sort) washer (flapper) that opens at 25lbs of Oil Cooler pressure.

Spring Loaded Oil Cooler Bypass ValueThe Brass Plunger shows scoring

The Wood Chip holds open the washer at the failure.

The Problem

According to FORD, these two small values are NOT replaceable parts !!

And therefore, normal Auto Parts stores do not have the parts, nor does FORD.

Our OCBV plastic/rubber seal is damaged, and the Brass Plunger is scored showing that it had failed long ago.

The values can only be replaced with a NEW Oil Cooler Cover, which is about $180.00, the plastic/rubber part, if available, should only cost about $2.00, even though it is about $0.10 worth of plastic/rubber.

My Conjecture

I suspect that the OCBV failure contributed to the EGR Cooler failure and therefore the need to repair this engine - it is a $0.10 part ?

Our Planned Fix

Google searches provided very little help or suggestions of a solution.

Our current plan is to create a new Teflon washer (value flapper). A Teflon rod is now on order. Experiments with different on-hand materials failed to hold up in a gas/oil environment. Teflon appears to have the right properties; inert and high temperature resistant.

Thanks FORD, my Son's truck has be on blocks for about three weeks now, while finding a workable solution.

End Rant

If this works as planned, I will be selling Teflon washer, and or Teflon Plunger with integrated Teflon Value seat, . . . soon :-).

Teflon Washer

Update:
The engine has now been running with the new Teflon Value Seat for several weeks, when the oil is changed it will be removed and inspected for ware.

Here is a photo of the Bypass Valve Assembly reinstalled ( I had forgotten I took this photo). The Oil Filter Tower and Canister have not been reinstall yet, as can be seen, two screws hold the assembly in place. Inspection for ware at the next oil change, will be easy.